Control apparatus



y 4, 1940. H. WALKER 2.200.728

CONTROL APPARATUS Filed April 18, 1938 2 Sheets-Sheet 1 INVENTOR. H oNAED NHL KER B 0 Arrozrmyg y 9 1940- H. WALKER 2.200.728

CONTROL APPARATUS Filed April 18, 1938 2 Sheets-Sheet 2 Con fro] Pbm'fFig. j

INVENTOR. BY How/7,90 NHL/(7? ATTORNEYS Patented Mi, 14, 1940 UNITED,STATES oon'mor. APPARATUS Howard Waller, Chicago, 111., assignor toBendix Radio Corporation, Chicago, 111;, a corporation I of DelawareApplication April 1a, was, Serial No. 202,682'

5 Claims. (oi. 172-239) This invention relates to control apparatus andmore particularly to motor powered apparatus which may be operated lroma remote point. The improved apparatus may be used for actuatingelectrical switches or for effecting other kinds of control functions.

An object of the invention is to provide improved apparatus in whichmotor power is used to move the controlling memberto some selectedposition and in which safeguards are provided forprcvcntingmovement ofthe control 7 member beyond the selected position.

y In motor powered control devices, it is a difficult problem to stopthe controlling member at exactly the desired position, as the momentumof the motor tends to carry the movement on after the motor isdeenergizeo, and this extra movement destroys the sccuracy of control inthe common control system. To overcome such periods and in which thecontrol member re-' mains motionless during the intervening periods.

- With this construction it is possible to stop the motor during theintervening periods and thus eliminate any actuation oi the controlmember due to the momentum oi. the motor and drive mechanism. As afurther safeguard against the mechanism being moved on into the nextperiod by the motor momentum, I provide means for throwing a reversetorque on the motor in case the mechanism should he moved by the forceof momentum beyond a. certain point in the intervening period.

I have found also that especially when the member may he driven asrapidly as may be desired, and may he stopped at pro-selected positionswith the positive guarantee that there can be no further movement todestroy the accuracy of the setting.

A further object is to provide improved apparatus in which the controlmember is rotatable, the driving means being adapted to rotate thisimproved device with the casing front removed;

member intermittently inlone direction to different angular positionscorresponding with different control functions. Other objects andadvantages will be apparent as the specification proceeds. 5

Av preferred embodiment of the invention is illustrated in theaccompanying drawings in which:

Figure l is a front elevational view of the Figure 2 is a plan view withthe casing shown, in section, the section being taken as indicated atline 2-2 of Figure 1;

Figure 3 is a rear elevational view showing one side of the rotaryswitch; V

Figure 4 is a detail view of the switch shown in Figure 3, the Viewbeing taken as seen from line 4-4 of Figure 2; v

Figure 5 is a detail view of the cam member employed for controlling themotor energizing circuits; and I Figure 6 is a schematic view showingthe wiring arrangement.

As illustrated, A designates a casing or frame; B, a motor for supplyingthe necessary power to actuate the mechanism; C, themovable controlmember by which the control functions are efiectecl; and D, the'drive'mechanism through which the power of the motor is made effective todrive the control member to diiierent posh so tions corresponding withthe control functions desired.

The frame or casing, A may be of any suitable material, preferablymetallic, and may he of any suitable form. As illustrated, casing Aincludes 35 a rear portion A1 having forwardly turned edges, and a frontportion A: having rearwarcily turned edges, these portions being adaptedto be fitted together to form an enclosure. The screws 86 which extendbetween portions A1 and A2 form means for securing these portions inplace.

At one end of the frame enclosure A. is an opening ll through whichelectrical connections n'lay be made and which is convenient for ininFigure 1 of the drawings.

produce rotation in the opposite direction. However, any suitable typeof motor which is equipped with a circuit for setting up a reversingtorque may be used. .In the embodiment illustrated, the motor shaft I3is provided with a worm gear i4 which makes engagement with the toothedgear I5 keyed to the driving shaft l6. Through this engagement rotationof the motor is caused to produce rotation of the driving shaft. It isobvious that other means for connecting the motor in mechanical driverelation with the driving shaft may be provided if so desired. I

. The control member C is illustrated in the form of a shaft havingflattened sides and extending through the rear frame portion A1. Withinframe A is a hollow cylindrical sleeve l1 into which the end of shaft Cis secured. This sleeve is equipped with a fiange ll on the front sideof which is secured the gear 20.

The gear 20 has its peripheral portion formed into the general shapeillustrated more clearly At spaced intervals along its periphery are therecesses 2| extending radially inward and having curved walls. It willbe noted also that the portions 22 between recesses 2| are also ofcurved contour so as to engage the surface of the cam 22 secured onshaft l6. Cam 22 has a circular periphery except for the flattened side22, and operates through engagement with the tooth portions 23 tomaintain gear 25 locked and motionless except when the side 22* isadjacent these portions.

Secured on the drive shaft 16 just rearward of cam 22 is the driving arm24 carrying. the forwardly extending pin 25. Arm 24 is aligned with thesurface 22 of cam 22 and is adapted to pass rearwardly of gear 20 asdriving shaft i6 rotates, the pin25 entering one of the recesses 2| tomove gear 20. It will be observed that when pin 25 is moved to actuategear 25, the side 22'- of the cam will have moved adjacent a peripheraltooth portion 23 so as to unlock the gear and leave it free to rotate;but as soon as pin 25 moves from the recess engaged, the circularsurface of cam 22 engages the next of tooth portions 23 to again lockthe gear against rotation.

Mounted in any suitable way in the frame are the spring contact fingers26' and 26 which normally maintain the contacts 26 closed, and also thespring fingers 21' and 21 which normally maintain the contacts 21 open.The spring fingers 26 and 21 have their end portions extending over thedriving shaft l5 and the lowermost'of these, 26'', is provided with anose 25.

which rides on the cam 40 secured on shaft I6.

The cam 40 is shown in detail in Figure 5 of the drawings. It has threearcuate peripheral surfaces each concentric with shaft l6 and ofdifferent radius. As shownin Figure 5, the cam surface is of smallestradius, the cam surface 40 of medium radius, and the cam surface 4|! oflargest radius. When the nose 28 rides on the surface 40, contacts 21are open and contacts 26 are closed; when nose 26 rides on surface 40',the contacts 25 are open as well as the contacts 21; and when nose 28rides on the surface 45", the contacts 26 are held open and contacts 21are closed. As clearly shown in Figure 5, the junction between each ofthese cam surfaces is rounded and smooth so that the nose 2! may passeasily from one cam surface to the other. Though as here illustratedeach of the above described surfaces extend over substantially equalparts of the cam periphery, this may be varied as may be desired. It isessential only that there be three successive cam positions forproducing the three conditions of the contacts 26 and 21 as abovedescribed.

. Mounted on the rear side of frame A and having its rotor engaging thecontrol shaft C, is the switch shown more clearly in Figures 3, 4 and 6.On the rear side of this switch (Figure 3) the rotor is provided withthree conductor segments 59 each of which has one. tooth. The contact 51mounted on the stator is adapted to make contact with the arcuate orinner part of the segment while the contacts 52 and 53 and 54 areadapted to make contact only with the tooth of a segment.

On the other side of the switch (Figure 4) the rotor is provided with anannular conductor 60 having three spaced peripheral recesses 61. Thecontact 55 mounted on the stator is adapted to make continuous contactwith the annular conductor irrespective of the peripheral recesses, butthe contacts 56, 51, -and 52 are adapted to contact conductor exceptwhen in register with one of the three recesses. Contacts 56, 51, and 56are connected around the edge of the switch stator to contacts 52, 53,and 54 respectively. Any other switching arrangement which is suitablefor performing the necessary switching functions may be substituted forthat above described.

As seen more clearly in Figure 6, one side of the supply line L isconnected through the normal motor field 10 to the contact 55. Fromcontact 55, the circuit may be traced to one of contacts56, 51 or 55,then to one of points 16, 11, or 18 of the control switch lli located atsome remote point, and return to the other side of the supply line byway of ground.

An auxiliary circuit through field 10 may also be traced from the saidside of the line through contacts 26 and return by way of ground. Thecircuit which when completed will produce a reverse torque on motor B,may be traced from the same one side of the supply line throughreversing field 1|, and through contacts 21 to contact 51; from contact51 to one of contacts 52,

53 or 54, thence to one of points 16, 11 or 15 on switch and return tothe other side of the supply line by way of ground.

The control shaft A may have associated therewith any number of rotaryswitches 50 of a type similar to switch 56 which have their rotorssecured to the shaft and have their stators mounted on some fixedsupport. The various electrical contacts on the stators of theseswitches may be connected to various circuit points in a radio receiver.With the contact points thus connected, it is clear that rotation of themember A operates to change the interconnection of these points, and inthis way the. improved apparatus is useful for conditioning a radio setfor operation on a selected one of several frequencies. It will beunderstood, however, that other and different control functions may beachieved by different connection with the device being controlled.

. Operation from one side of the supply line through the normal field10, and contacts 56 and 16 to ground.

Note that at this instant nose 26 is engaging the intermediate camsurface and both contacts 26 and 21 are in open condition, thusrendering both the auxiliary and reversing circuits ineffective. Beingenergized through its normal field, the motor A beginsto rotate andthrough the worm gear arrangement drives the shaft IS in a directionwhich is counterclockwise as seen in Figure 1. Upon rotation of shaftIS, the cam surface 40 is brought into contact with nose-'28 and thiscloses contacts 21. This is of no effect, however, for at this timethere is no path between contact 53 and ground, the remote controlswitch being on point 16.

As was before stated the control member remains locked in one positionthrough the engagement between the cam 22 and-one of the tooth portions23 on gear until the arm 24 has moved to bring pin 25 into contact withthe walls of one of the recesses 2|; After gear 20 has been movedthrough rotation of the arm 24 and at or just before the time the'pin 25has disengaged from the recess of gear 2|], the rotor of switch 50 willhave been turned tobring one of recesses SI into register with contact56 and the original energizing circuit will be broken; but before thistime the lower cam surface 40* will have moved into engagement with nose28 and contacts 25 will thus have been closed to maintain circuit. Afterthe pin 25 has left the recess in gear 20, the intermediate cam surface40' will come into engagement with the nose 28 to open contacts 26 andthis operates to de-energize the normal field 10. Thus the motor isdeenergized at a time after thecontrol member has reached its newposition and has been locked there. It

is intended that the motor should coast to a stop while the intermediatecam surface 66'" is in engagement with nose 28, but if through motormomentum, movementshould continue until the higher cam surface 40 shouldcome into engagement with nose 28,-this will operate to close a circuitwhich energizes the reversing field M. This latter circuit may be tracedfromone side of the supply line through field 7i and contacts 21 tocontact 51, and thence through contacts 52 and 16 to ground. I'hiscircuit will be completed only instantaneously, for once the circuit iscompleted, the reverse torque on the motor will quickly move the camsurface 48 back out of contact with the nose 28 to again open thiscircuit.

If then, the operator at the remote point should move control switch 80back to point 11, a circult would be completed as before through thenormal field ll] of the motor. .When the next succeeding of recesses Siin conductor ring 66 comes into register with contact 51, this originalcircuit is broken and energization of fleldlii continued through theauxiliary circuit until cam 40 operates to open contacts 25 after whichthe motor is stopped as before. With switch 50 arranged as hereindescribed, this latter position of the control member will be removed120 from the position first considered. A consideration of otherpositions to which the control member may be moved discloses that thereare three angular positions of this member which correspond with each ofthe three points on the control switch as. In this particular embodimentit'is contemplated that the shaft C may be arranged to actuate therotors of switches having four settings which givethe same electricalconnections so that the control functions effected are repeated in each120 of the shaft movement, but the arrangement may be otherwise if sodesired. For exampia the gear 20 might be arranged with only fourrecesses instead of the twelve as shown; only one sector 59 might beused instead of the three as shown;

ring 50 might have but one recess BI; and a control switch of fourpoints might be used instead of the three-point switch as shown. In

this example, each of the points of the control switch would have anindividual control shaft position with which they correspond, and theoperation of the motor deenergizing means for stopping the mechanismwith the shaft, in a seis important that the radial position of thepinor projection 25 bear such relation to the periphery of gear 20 thatthis gear is moved the desired angular distance at one turn of themember on which this pin is carried.

While I have shown butone embodiment of the improved device, it isobvious that many other embodiments might be constructed, and manychanges may be made in arrangement and construction without departingfrom the spirit of the invention.

The foregoing detailed description has been given for clearness ofunderstanding only, and

no unnecessary limitations should be understood therefrom, but theappended claims should be construed as broadly as permissible in view ofthe prior art.

I claim:

1. Control apparatus of the character set forth comprising: a movablecontrol member, an electric motor, drive means actuated by said motorfor driving said member during periods in the operation of said motorbut not during intervals between said periods, circuit means forenergizing said motor for movement in one direction, cam means fordeenergizing said motor after said member has been moved to a selectedone of a plurality of positions and at a predetermined point in theoperation of said motor during one of said intervals, and cam meansoperable subsequent to said first-mentioned cam means for energizingsaid motor for movement in a reverse direction whereby movement of saidmotor into the next of said periods of operation is prevented.

2. Apparatus as set forth in claim 1 inwhich each of said cam means havea common cam member which member is actuated by said motor.

3. Remote control apparatus of the character set forth comprising: aframe, a control shaft rotatably mounted in said frame, a gear membersecured to said shaft and having peripheral recesses therein, anelectric motor having a reversing field, a driving member rotatablymounted in said frame, said driving member having a projection adaptedto engage said peripheral recesses in the gear member to rotate saidgear member as said driving member is rotated, means connecting saiddriving member in mechanical connection with said motor, circuit meansfor energizing said motor for forward movement, means for deenergizingsaid motor after said member has been moved to a selected one of aplurality of positions and at a predetermined point in the operation ofsaid motor during one of said intervals, said means including a cammember rotatable with said driving member, means operable onlysubsequently to the operation of said deenergizing means and in theevent that said driving member moves on to a predetermined point in saidinterval for temporarily energizing the reversing field of said motorwhereby movement of said motor into the next of said periods ofoperation is prevented, said means in.- cluding said cam member, andlocking means for holding said gear motionless during said intervals,said locking means including a cam member rotatable with said drivingmember.

4. In a selective control system having a plurality of controlpositions, a reversible electric motor, a shaft driven by said motor, anintermittent motion mechanism actuated by said shaft a control membermovable into said control positions and actuated by said mechanism,switch means for selecting any one of said control positions andenergizing said motor, a cyclic switch aaoopaa operated Dy-said drivenshalt, said cyclic switch having means for deenergizing said motor durins its first cycle of operation after attainment of said selectedcontrol position and for establishing a reversing circuit upon overrunof said motor.

5. In a selective control system having a plurality of controlpositions, a, reversible electric motor, a shaft driven by said motor,an intermittent motion mechanism actuated by said shaft, 9, controlmember movable into said control positions and actuated by saidmechanism, switch means for selecting any one of said control positionsand energizing said motor, a second switch operated by said driven shaftin timed relation with respect to said intermittent motion mechanism,and cam means associated with said second switch for deenergizing saidmotor after attainment of said selected control position and forestablishing a reversing circuit upon overrun of said motor.

HQWAHD

